A team of Australian researchers from the University of New South Wales (UNSW) has tested in guinea pigs that the cochlear implant associated with a neuroregenerative substance helps to improve hearing when suffering from profound deafness .
The objective of the work, published in the journal Science Translational Medicine , is to improve the efficacy of cochlear implants, combining them with gene therapy . The cochlear implant is a high-tech transducer that transforms acoustic signals into electrical signals that stimulate the auditory nerve.
These signals are processed by the different pieces that make up the cochlear implant, some of which are placed inside the skull and others outside. The device helps people who are deaf or hard of hearing to hear. It differs from hearing aids in that it is surgically implanted and works differently.
In the experiment carried out with totally deaf guinea pigs , the team led by Gary Housley, director of the department of Neuroscience at the aforementioned University, used a type of therapy called electrogenetic delivery, which uses electric fields to precisely locate genes near the cells. electrodes on the cochlea.
The scientists injected a DNA solution containing so-called brain-derived neurotrophic factor, a protein encoded by the BDNF gene, into the cochlear implants of guinea pigs, and applied electrodes to conduct a few short electrical pulses to the cochlea. According to Housley, “within a few hours, the cells of the cochlea took up the DNA and began to express neurotrophins, proteins that help the development of nerve cells.”
The researchers then subjected the animals to hearing tests, using the auditory brainstem response (ABR) technique, commonly used for this type of measurement in newborns. As expected, they saw a marked improvement in hearing . Deaf animals recovered their hearing to almost normal levels . This technique could help improve the quality of sound perception in implant patients in the future. And is that, according to Housley, “those with cochlear implants understand speech well, but do not perceive the richness of the range of sounds and do not usually enjoy the pleasure of music, for example.”
Australian scientists, who are already organizing clinical trials of the new technique, believe that it could also be used in combination with other bionic devices such as electrodes used in deep brain stimulation for the treatment of Parkinson’s disease and depression, among other disorders.
